<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>keyevent</title>
</head>
<body>
    <div id="app">
    <button @click="show = !show">点击切换</button>
        <span v-if="show">cnm</span>
        <span v-show="show">v-show</span>
    </div>
</body>
<script src="../node_modules/vue/dist/vue.js"></script>
<script>
    let vm = new Vue({
        el:"#app",
        data:{
            show:true
        },

    })
</script>
</html>